Storage device for generating and storing description information of multi-media contents including keywords in which duplicative keywords are replaced by reference information, and a computer readable storage medium for causing a computer to function as the storage device and to locate selected keywords in said multi-media content

ABSTRACT

There are provided a storage device and a computer-readable medium capable of efficiently storing keywords contained in description information and efficiently retrieving the keyword. A list producing portion ( 6 ) extracts the keywords from the description information and produces a keyword list correlating the keywords with the scene information containing the keywords. A description information converter ( 8 ) converts the keywords contained in the keyword list received from the list producing portion ( 6 ) among the keywords contained in the externally received description information into reference information for specifying the keywords in the keyword list received from the list producing portion ( 6 ). A storage ( 10 ) stores the converted description information provided from the description information converter ( 8 ) and the keyword list provided from the list producing portion ( 6 ).

This application is a divisional application of copending U.S. patentapplication Ser. No. 11/667,815, entitled STORAGE DEVICE AND RECORDINGMEDIUM by Shuichi Watanabe and Jiro Kiyama, the same inventors as theinventors of this divisional application, filed on 15 May 2007, whichapplication claims priority from International ApplicationPCT/JP2005/020289 dated 4 Nov. 2005 and Japanese Application No. JP2004-351558 dated 3 Dec. 2004.

TECHNICAL FIELD

The present invention relates a storage device and a computer-readablemedium, and particularly to a storage device and a computer-readablemedium that efficiently store description information describing detailsof multimedia.

BACKGROUND ART

Owing to increase in capacity of movie recording devices and widespreaduse of fast/broad-band networks in recent years, a large amount ofmovies have been handled more often than ever, and therefore a mannerfor efficiently retrieving and managing movies has been required.

Intrinsically, a movie is searched for details of scenes containedtherein. For such searching or retrieval, it is necessary to replaysuccessively the movie and determine the details. However, this is notpractical for a large amount of movies. Therefore, descriptioninformation describing details of movies are prepared in advance foreach movie so that the movie retrieval can be performed based on thedescription information.

As disclosed in Japanese Patent Laying-Open Nos. 05-282379 (patentreference 1) and 08-110912 (patent reference 2), the descriptioninformation is often configured as data having a tree structure forallowing easy retrieval.

FIG. 1 illustrates an example of conventional description information.

Referring to FIG. 1, a whole movie is formed of four scenes [1]-[4]. Foreach scene, the description information describes time information(start time and length) of the scene, a title of the scene and actorsappearing in the scene.

Based on the above description information, a user can know that anactor “Keiko KUBO” appears in a scene [1], and can reproduce the scene[1] in which “Keiko KUBO” appears, from the whole movie according to thetime information of “start time: 00:00:00, length: 3 mins” of the scene[1]. As described above, the description information is very effectiveat the movie retrieval.

FIG. 2 illustrates details of the description information dataillustrated in FIG. 1.

Referring to FIG. 2, the actual description information is given as datastrings, and each of items in each scene is individually described asthe data. The individual data describing details of each item such asnames of actors will be referred to as a “keyword”.

Patent reference 1: Japanese Patent Laying-Open No. 05-282379

Patent reference 2: Japanese Patent Laying-Open No. 08-110912

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, from the keywords in the description information illustrated inFIG. 1, and particularly from the keywords representing the actors, itcan be seen that some of the actors appears in a plurality of scenes.

More specifically, even when a keyword in a certain scene is the same asa keyword included in another scene, each of these keywords is recordedas an independent keyword so that the description information becomesredundant and large in total quantity.

The invention has been made for overcoming the above problem, and anobject of the invention is to provide a storage device and acomputer-readable medium that can efficiently store keywords included indescription information.

Means for Solving the Problems

According to the invention, a storage device for storing descriptioninformation describing details of multimedia contents and including akeyword, includes a description information converter providing aconverted description information by converting the keyword in thedescription information into reference information for specifying thekeyword; and a storage storing a list correlating the keyword with thereference information and the converted description information providedfrom the description information converter.

Preferably, the storage device further includes a list producing portionproducing the list by extracting the keyword in the descriptioninformation.

Preferably, the storage device further includes a position informationextractor extracting position information indicating a position, in themultimedia contents, of the keyword to be converted into the referenceinformation by the description information converter, and the storagefurther stores the position information extracted by the positioninformation extractor.

Preferably, the list producing portion adds the position informationextracted by the position information extractor to the list in such afashion that the position information is correlated with the keyword.

Preferably, the list producing portion adds the position informationextracted by the position information extractor to the list in such afashion that the position information is correlated with the referenceinformation specifying the keyword.

Preferably, the description information converter converts, in additionto the reference information, the position information indicatinganother position of the same keyword in the multimedia contents as thekeyword to be converted into the reference information, based on theposition information extracted by the position information extractor.

Preferably, the description information converter converts a listcorrelating the keyword with the reference information in addition tothe description information.

According to the invention, a storage device for storing descriptioninformation describing details of multimedia contents and includingkeywords, includes a description information converter converting eachof a plurality of the same keywords included in the descriptioninformation except for at least one of the same keywords into referenceinformation specifying the above at least one keyword; and a storagestoring the converted description information provided from thedescription information converter.

Preferably, each of the at least one keyword in the descriptioninformation bears ID information representing itself, and the referenceinformation specifies the at least one keyword by indicating the IDinformation.

According to the invention, a computer-readable medium bears descriptioninformation describing details of multimedia contents and including akeyword. The description information includes description datadescribing details of the multimedia contents using referenceinformation for specifying the keyword instead of using the keyword; anda list correlating the keyword with the reference information.

Preferably, the description information further includes position datarepresenting a specific position, in the multimedia contents, of each ofthe keywords described using the reference information.

Preferably, the position data is added to the list in such a fashionthat the position data is correlated with each of the keywords.

Preferably, the position data is correlated with the referenceinformation specifying each of the keywords in the list.

Preferably, the description data includes position data representing aspecific position, in the multimedia contents, of the same keyword asthe keyword described using the reference information.

Preferably, the description data includes a list correlating the keywordwith the reference information.

According to the invention, a computer-readable medium bears descriptioninformation describing details of multimedia contents and including akeyword. The description information is formed by replacing each of aplurality of the same keywords included in the description informationexcept for at least one of the same keywords with reference informationspecifying the at least one of the keywords.

Preferably, each of the above at least one keyword in the descriptioninformation includes ID information representing itself, and thereference information specifies the at least one keyword by indicatingthe ID information.

Effects of the Invention

According to the invention, since the details of the multimedia contentsare described using the reference information specifying the keywordincluded in the description information instead of using the keyword,the data quantity of the keywords included in an overlapping fashion canbe reduced to a data amount of the reference information, and the dataof the whole description information can be reduced. Therefore, thekeywords included in the description information can be efficientlystored.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of conventional description information.

FIG. 2 illustrates details of the description information dataillustrated in FIG. 1.

FIG. 3 shows a schematic structure of a storage device according to afirst embodiment of the invention.

FIG. 4 illustrates an example of a keyword list produced by a listproducing portion.

FIG. 5 illustrates the keyword list obtained after all the descriptioninformation in FIG. 1 is processed.

FIG. 6 illustrates the description information obtained after thekeywords in the description information in FIG. 1 are converted into thereference information.

FIG. 7 is a flowchart illustrating processing of the storage device.

FIG. 8 illustrates an example of a display for performing movieretrieval.

FIG. 9 illustrates a manner of referring to the description informationand the keyword list.

FIG. 10 schematically shows a structure of a storage device according toa second embodiment of the invention.

FIG. 11 shows an example of a credit list annexed to the movie.

FIG. 12 illustrates examples of description information, the credit listand a keyword list according to the second embodiment of the invention.

FIG. 13 illustrates examples of description information, a credit listand an entry list according to a third embodiment of the invention.

FIG. 14 illustrates an example of description information according to afourth embodiment of the invention.

FIG. 15 shows a schematic structure of a storage device according to afifth embodiment of the invention.

DESCRIPTION OF THE REFERENCE SIGNS

-   -   2 and 52 keyword determining portion, 4 and 54 position        information extractor, 6 and 56 list producing portion, 8 and 58        description information converter, 10 and 60 storage, 12        description information producing device, 20 CPU, 28 interface,        30 communications device, 32 input, 34 output, 36 bus, 40        computer, 100, 102 and 104 storage device, 201, 301, 408, 414,        508 and 902 ID information, 202 and 410 keyword value, 203 and        416 scene information, 400 and 500 description information, 402,        502 and 902 reference information, 406 credit list, 412 keyword        list, 504 link information, 506 entry list.

BEST MODES FOR CARRYING OUT THE INVENTION

Embodiments of the invention will now be described with reference to thedrawings. The same or corresponding portions bear the same referencenumbers, and description thereof is not repeated.

First Embodiment

FIG. 3 shows a schematic structure of a storage device 100 according toa first embodiment.

Referring to FIG. 3, a storage device 100 receives descriptioninformation from a description information producing device 12. When amovie already including the description information is provided,description information producing device 12 can be eliminated. Storagedevice 100 is formed of a keyword determining portion 2, a positioninformation extractor 4, a list producing portion 6, a descriptioninformation converter 8 and a storage 10.

Keyword determining portion 2 determines whether a keyword included inthe externally received description information is present in a keywordlist received from list producing portion 6 or not. When the keywordincluded in the externally received description information is notpresent in the keyword list, keyword determining portion 2 provides thekeyword in question and an instruction for newly registering thiskeyword to list producing portion 6. When the keyword included in theexternally received description information is present in the keywordlist, keyword determining portion 2 provides information specifying thekeyword in the keyword list and an instruction for additionallyregistering this keyword, to list producing portion 6. The keyword thatis determined to be registered is provided to position informationextractor 4 by keyword determining portion 2.

From the description information, position information extractor 4extracts data representing scene information as to where the keywordthat is provided from keyword determining portion 2 for the newregistration or additional registration is contained, and provides theextracted data to list producing portion 6.

List producing portion 6 produces a keyword list that correlates thekeyword with the scene information as to where the keyword in questionis contained. When list producing portion 6 receives the keyword and theinstructions for newly registering the received keyword from keyworddetermining portion 2, it registers the keyword in the keyword list, andfurther registers the scene information received from positioninformation extractor 4 in a fashion related to the registered keyword.When list producing portion 6 receives the information specifying thekeyword and the instructions for additionally registering the receivedkeyword from keyword determining portion 2, it adds the sceneinformation received from position information extractor 4 to the listin a fashion related to the keyword. Further, list producing portion 6provides the keyword list thus produced to description informationconverter 8 and storage 10.

Description information converter 8 converts the keyword that is amongthe keywords in the externally received description information andparticularly is included in the keyword list received from listproducing portion 6. By this conversion, description informationconverter 8 produces the reference information for specifying thekeyword in the keyword list received from list producing portion 6, andprovides the converted description information to storage 10.

Storage 10 stores the converted description information provided fromdescription information converter 8 and the keyword list provided fromlist producing portion 6.

Description information producing device 12 produces the descriptioninformation from the movie provided thereto. For example, descriptioninformation producing device 12 may be configured to analyze the inputmovie, e.g., using a movie recognizing technology, and thereby producethe description information, or may be configured such that a userprovides the description information while recognizing the movie.

(Keyword List Producing Processing)

Storage device 100 according to the first embodiment receives theconventional description information illustrated in FIG. 1, and producesthe keyword list as described below.

Referring to FIG. 1, the keywords representing the actors describesspecific names of the actors, and the same data repetitively appears ina plurality of scenes.

Therefore, for retrieving scenes in which the same actor “Wataru WADA”appears, it is necessary to determine throughout the descriptioninformation whether the keyword “Wataru WADA” is present or not.Therefore, the retrieval requires a long time, and lowers a performancefor other processing during the retrieval processing. Accordingly,processing is performed to produce a keyword list additionally includinginformation about positions where the same keywords are present.

According to the first embodiment, processing is performed primarily onthe keywords that may repetitively appear in the descriptioninformation. The processing is performed on some other items such as“character names”, i.e., names of characters in the movie and “objectnames”, i.e., names of objects appearing in the movie.

In an ordinary case, it is merely required to perform the keyworddetermination on the same items, and the determination on differentitems is not required, e.g., for the following reason. Since each actoris assigned a character name in a play or the like, each keyword storedin the “character names” differs from any keyword stored in the “actors”except for the case where the actor's name is used as the character nameas it is.

FIG. 4 illustrates an example of a keyword list produced by listproducing portion 6.

FIG. 4( a) represents new registration in the keyword list.

FIG. 4( b) represents additional registration in the keyword list.

Referring to FIG. 4( a), list producing portion 6 produces an IDinformation 201, a keyword value (value) 202 and scene information(scenes) 203.

ID information 201 stores information for specifying the keywordsincluded in the list.

Keyword value 202 stores the keywords.

Scene information 203 stores information about scenes in which thekeywords stored in keyword value 202 are present.

FIG. 4( a) relates to the description information in FIG. 1, andparticularly illustrates a change in keyword list that occurs when asecond keyword “Keiko KUBO” is provided to storage device 100 that isalready provided with an initial keyword “Akira ABE” described in theitem of the actors.

Referring to FIGS. 3, 4(a) and 1, when the second keyword “Keiko KUBO”described in the item of the actors is provided to storage device 100,keyword determining portion 2 provides the keyword “Keiko KUBO” and aninstruction for newly registering to list producing portion 6 becausethis keyword “Keiko KUBO” is not present in the keyword list receivedfrom list producing portion 6. Also, keyword determining portion 2provides the keyword “Keiko KUBO” to position information extractor 4.

Position information extractor 4 receives the keyword “Keiko KUBO”determined by keyword determining portion 2, extracts the sceneinformation storing this keyword and provides a scene number “1” to listproducing portion 6.

List producing portion 6 performs new registration in the keyword listaccording to the keyword “Keiko KUBO” received from keyword determiningportion 2 and the instruction for new registration as well as the scenenumber “1” received from position information extractor 4.

Thereby, the keyword “Keiko KUBO” and the scene number “1” are stored inthe keyword list produced by list producing portion 6 with an ID number“2”.

FIG. 4( b) relates to the description information illustrated in FIG. 1,and particularly illustrates the change in keyword list that occurs whena keyword “Wataru WADA” of a scene [2] is provided in such a state thatall the keywords stored in the item of the actors of the scene [1] arealready provided to storage device 100.

Referring to FIGS. 3, 4(b) and 1, when an initial keyword “Wataru WADA”stored in the item of actors of the scene [2] is provided to storagedevice 100, keyword determining portion 2 provides an ID number “3” andan instruction for additional registration to list producing portion 6because the keyword “Wataru WADA” is present at the ID number “3” in thekeyword list received from list producing portion 6. Keyword determiningportion 2 provides the keyword “Wataru WADA” to position informationextractor 4.

Position information extractor 4 receives keyword “Wataru WADA”determined by keyword determining portion 2, extracts the sceneinformation storing the keyword and provides a scene number “2” to listproducing portion 6.

List producing portion 6 stores the scene number “2” in the rowdesignated by the ID number “2” received from keyword determiningportion 2.

Thereafter, list producing portion 6 produces the keyword list from theexternally provided description information in a similar manner.

FIG. 5 illustrates the keyword list obtained after all the descriptioninformation in FIG. 1 is processed.

FIG. 5( a) illustrates a list form.

FIG. 5( b) illustrates the details of the list illustrated in FIG. 5( a)in a form of description information.

Referring to FIG. 5( a), list producing portion 6 produces a list thatrelates to the keywords stored in the item of the actors included in thedescription information illustrated in FIG. 1, and this list correlateseach keyword with the scene information storing the keyword in question.

Referring to FIG. 5( b), list producing portion 6 may provide thedetails of the list illustrated in FIG. 5( a) in the descriptioninformation form.

In the foregoing description, the scene numbers allocated to therespective scenes are handled as the position information to be handledas the scene information in the contents. For example, when amulti-level or hierarchical structure in which each scene is subdividedinto sub-scenes, two-dimensional data (M, N) representing a sub-scene Nof a scene M may be handled as the scene information (positioninformation). An expression form of “/scene M/sub-scene N” representinga path in the tree structure may be handled as the scene information(position information). Further, a start time of the like of the scenemay be handled as the position information.

In the above example, ID information 301 of the keywords is formed ofconsecutive numbers assigned to the respective keywords. However,another information may be employed provided that it can distinguisheach keyword from the others. Further, ID information 301 is notessential, and the list may consist of only a keyword value 302 andscene information 303. In this case, keyword value 302 itself is used asthe information for the keyword distinction.

The purpose of producing the keyword list in FIG. 5( a) is to avoidoverlapping of the same keywords recorded in the description informationand to avoid increase in data quantity due to such overlapping.Therefore, the data quantity can not be effectively reduced inconnection with a keyword such as “Keiko KUBO” that appears only once inthe description information as illustrated in FIG. 5( a). Accordingly,list producing portion 6 may perform the processing of eliminating thekeywords not overlapping in the description information from the list.

Keyword determining portion 2 may receive the description information inwhich each keyword has already born a flag indicating whether thekeyword is to be registered in the keyword list or not, and thereby maydetermine according to the flag whether the keyword is to be registeredin the keyword list or not. For example, keyword determining portion 2receives, for each keyword included in the description information, thedescription information bearing a flag indicating that the keyword inquestion appears only once in the description information or that itappears multiple times, and determines according to the value of theflag not to register the keyword appearing only once in the keywordlist. Thereby, the keyword appearing only once does not require thedetermination with respect to the keyword registered in the keyword listso that the processing can be performed faster.

Further, the order of the keywords in the keyword list produced by listproducing portion 6 may be the same as that of the appearance in thedescription information, but the keywords may be arranged in thedictionary order (the alphabetical order or the order of the Japanesesyllabary). It can be expected that the arrangement of the keywords inthe dictionary order can further improve the retrieval efficiency.

(Conversion Processing of Description Information)

FIG. 6 illustrates description information prepared by converting thekeywords in the description information illustrated in FIG. 1 into thereference information. In FIG. 6, the portions converted from those inthe description information illustrated in FIG. 1 are illustrated in anenhanced forms.

FIG. 6( a) illustrates a tree structure.

FIG. 6( b) illustrates the description information of the tree structureillustrated in FIG. 6( a) in a data form.

Referring to FIGS. 3, 5(a) and 6(a), description information converter 8receives the keyword list from list producing portion 6, and convertsthe keywords included in the externally provided description informationinto reference information 402 used for specifying the keywords inquestion in the keyword list. Description information converter 8provides the converted description information to storage 10.

In the first embodiment, the ID number stored in ID information 301 inthe keyword list illustrated in FIG. 5( a) is used as referenceinformation 402.

As described above, by using the keyword list produced by list producingportion 6 and the description information converted into the referenceinformation, the same details as those described in the originaldescription information can be stored while reducing a data quantity.

When a plurality of lists are present, it is desired that theinformation for specifying the keyword list itself is employed as thereference information in addition to ID number 301 of the keyword list.

As the reference information, the position of the path in thedescription information format illustrated in FIG. 5( b) may be usedinstead of the foregoing ID number. Further, the keywords stored in thekeyword list may employ actual data record positions (absolute addressesof data or relative addresses from a fixed position). When the list andthe description information are recorded on the same record medium, theoffset distances between the reference information and the keywords inthe list may be employed.

Description information converter 8 that converts the keyword in thedescription information into the reference information may also convertthe keyword into the keyword and the reference information. Thus, it maybe configured to add the reference information while holding thekeyword.

A comparison may be made between the data quantity of the keywords andthe data quantity of the reference information, and the keywords or thereference information having a smaller data quantity may be used so thatthe whole data quantity can be reduced. Accordingly, descriptioninformation converter 8 may be configured to select the operation, i.e.,to convert each keyword to the reference information or to use thekeyword as it is, before converting the keyword into the referenceinformation. In this case, it is desired that the descriptioninformation additionally includes additional information such as a flagindicating that the keyword data itself is recorded, or that theconverted reference information is recorded.

(Whole Processing Flow of Storage Device)

FIG. 7 is a flowchart illustrating the processing of storage device 100.

Referring to FIG. 7, keyword determining portion 2 extracts the keywordfrom description information, and provides the extracted keyword toposition information extractor 4 (step S100).

Position information extractor 4 extracts the scene informationcorresponding to the keyword provided from keyword determining portion 2(step S101). Position information extractor 4 provides the extractedscene information to list producing portion 6.

Keyword determining portion 2 determines whether the extracted keywordis present in the keyword list received from list producing portion 6 ornot (step S102).

When the extracted keyword is not present in the keyword list (NO instep S102), keyword determining portion 2 provides the keyword and aninstruction for newly registering the keyword to list producing portion6. Thereby, list producing portion 6 newly registers the keywordreceived from keyword determining portion 2 and the scene informationreceived from position information extractor 4 in the keyword list (stepS104).

When the extracted keyword is present in the keyword list (YES in stepS102), keyword determining portion 2 provides the information specifyingthe keyword in question and the instruction for additionally registeringthe keyword to list producing portion 6. Thereby, list producing portion6 additionally registers the scene information received from positioninformation extractor 4 in a fashion related to the keyword that isalready registered and is specified by the specifying informationreceived from keyword determining portion 2 (step S106).

Since no keyword is registered in the initial state, the keyword that isfirst read is always newly registered.

List producing portion 6 determines whether the reading of thedescription information has ended or not (step S108).

When the reading of the description information has not ended (NO instep S108), list producing portion 6 provides an instruction forcontinuing the keyword extraction. Thereby, keyword determining portion2 continues the keyword extraction from the description information(step S100).

When the reading of the description information has ended (YES in stepS108), list producing portion 6 notifies description informationconverter 8 of the end of the description information reading, andprovides the produced keyword list to storage 10. Thereby, descriptioninformation converter 8 converts the keyword data in the externallyprovided description information into the reference information for thekeyword list, and provides it to storage 10 (step S110).

Storage 10 stores the converted description information provided fromdescription information converter 8 as well as the keyword list providedfrom list producing portion 6 (step S112).

(Retrieval of Description Information)

Description will now be given on the case where the movie retrieval isperformed using the description information stored in a storage 100according to the first embodiment.

FIG. 8 illustrates an example of a display for performing the movieretrieval.

FIG. 9 illustrates a manner for referring to the description informationand the keyword list.

Referring to FIGS. 8 and 9, the user provides an instruction forstarting a retrieval process while an intended scene is being replayedor paused (step S200). The retrieval process thus started obtains thescene information at the time of reception of the user's startinstruction (step S202). The retrieval process obtains a data typeincluded in the obtained scene (step S204). Further, the retrievalprocess describes a retrieval display according to the obtained datatype (step S206).

The user selects the data type used for the retrieval on the display.For example, the user selects the data type of the actor. Thereby, theretrieval process obtains the keywords included in the selected datatype (step S208). Further, the retrieval process describes the keywordsincluded in the selected data type on the retrieval display (step S210).

Further, the user selects the intended keyword. For example, the userselects the keyword “Akira ABE”. Thereby, the retrieval process obtainsthe scene information in the description information containing theselected keyword (step S212). The retrieval process displays the sceneincluding the keyword selected by the user, based on the obtained sceneinformation (step S214).

Finally, the user selects the intended scene for replay. For example,the user selects a scene [3].

Through the above retrieval steps, the user can replay the intendedscene.

In the foregoing first embodiment, as illustrated in FIG. 1, thedescription information includes, for each scene, the time information(start time and length), the title and the information of the actorsappearing in the scene. However, the structure and details of thedescription information are not restricted to the above. For example,the description information may have a multi-level or hierarchicalstructure in which each scene is subdivided into sub-scenes. Also, thedescription information may additionally include, as the informationbelonging to the scene, feature information such as a representativecolor and a degree of motion, in addition to text information such as acommentary. Instead of the tree that represents one movie as a whole, atree structure may be configured such that a root node (highest node)represents all programs broadcasted on one channel, divided nodes at thefirst level represent the programs, respectively, and each of dividednodes at the second level represents the scene included in the program.

As illustrated in FIG. 3, it has been described that the descriptioninformation that is prepared in advance is received and converted.However, the process may be configured to perform the analysis in thesame stage as the production of the description information, and toperform simultaneously the production of the keyword list and theconversion into the reference information.

According to the first embodiment, the details of the multimediacontents are described using the reference information specifying thekeywords instead of using the keywords included in the descriptioninformation. Therefore, the data quantity of the keywords that areincluded in the description information in the overlapping fashion canbe reduced to the data quantity of the reference information, and thedata quantity of the whole description information can be reduced.Accordingly, the keywords included in the description information can beefficiently stored.

According to the first embodiment, the keyword list stores all the sceneinformation including the keywords. Therefore, even when the keywordincluded in the overlapping fashion in the description information is tobe retrieved, the scene information including the keyword in questioncan be obtained using the keyword list. Accordingly, it is not necessaryto search the whole description information for the keyword, and theretrieval can be performed efficiently and rapidly.

According to the first embodiment, it is not necessary to reregister thekeyword included in the description information that is once registeredin the keyword list. Therefore, the description information can beprepared while avoiding such a problem that an intended scene cannot beretrieved due to misspelling during entry of the same keyword.Accordingly, it is possible to prevent lowering of the retrievalprecision that may be caused by a mistake in entry during production ofthe description information. Further, the keywords included in thedescription information can be edited only by editing the details of thekeyword list so that the description information can be efficientlyedited.

Second Embodiment

The first embodiment has been described in connection with the casewhere the keywords are extracted from description information to producethe keyword list.

A second embodiment will now be described in connection with the casewhere a list formed of keywords included in description information isprovided in advance.

In some cases, movie contents include, as production information, acredit list including a list of actors of the movie and the like.

When the credit list is annexed, the keyword list is not produced, andreference information referring to the annexed list is used.

FIG. 10 schematically shows a structure of a storage device 102according to a second embodiment.

Referring to FIG. 10, storage device 102 externally receives thedescription information and the credit list. Storage device 102 isformed of a keyword determining portion 52, a position informationextractor 54, a list producing portion 56, a description informationconverter 58 and a storage 60.

Keyword determining portion 52 extracts the keyword included in theexternally received description information, and obtains the referenceinformation that specifies the extracted keyword in the externallyreceived credit list. Keyword determining portion 52 provides thisreference information to list producing portion 56 and positioninformation extractor 54.

Position information extractor 54 receives the keyword determined bykeyword determining portion 52, extracts the data, representing sceneinformation storing this keyword, from the description information andprovides it to list producing portion 56.

List producing portion 56 externally receives the credit list. Listproducing portion 56 produces a keyword list that correlates thereference information specifying the keywords in the credit list withthe scene information storing the keywords. List producing portion 56adds the scene information received from position information extractor54, and correlates it with the reference information received fromkeyword determining portion 52. Further, list producing portion 56provides the keyword list thus produced to storage 60.

Description information converter 58 replaces the keywords that areincluded in the externally received description information andparticularly are included in the externally received credit list withthe reference information for specifying the keywords in the creditlist. Description information converter 58 provides the converteddescription information to storage 60.

Storage 60 stores the converted description information provided fromdescription information converter 58 as well as the keyword listprovided from list producing portion 56.

FIG. 11 illustrates an example of the credit list annexed to the movie.

Referring to FIG. 11, the keywords included in the items of thedescription information are stored on an item-by-item basis.

FIG. 12 illustrates examples of description information 400, a creditlist 406 and a keyword list 412 according to the second embodiment.

Referring to FIGS. 10 and 12, credit list 406 is formed of IDinformation 408 and a keyword value 410. Description informationconverter 58 converts the keywords included in description information400 into reference information 402 for specifying the keywords in creditlist 406. Reference information 402 is ID information 408 in credit list406.

Therefore, the keyword of keyword value 410 included in credit list 406can be specified using reference information 402.

Keyword list 412 is formed of ID information 414 that is the same as IDinformation 408 in credit list 406 as well as scene information 416.List producing portion 56 adds the scene information received fromposition information extractor 54 and correlates it to the referenceinformation received from keyword determining portion 52.

Since reference information 402 specifying the keywords in credit list406 and scene information 416 are recorded in a correlated fashion, IDinformation 408 of credit list 406 is obtained according to the keywordrequired by the user, and scene information 416, corresponding to IDinformation 414 that is the same as ID information 408 thus obtained, isobtained in keyword list 412. Thereby, the scene information containingthe keyword in question can be retrieved.

Keyword list 412 includes ID information 414 for establishing thecorrelation with the keywords recorded in credit list 406. However, thekeyword list may have the rows arranged in the same order relationshipas the keywords in the credit list, whereby the ID information 414 canbe eliminated.

According to the second embodiment, the keyword list is produced bycorrelating the reference information specifying the keywords in thecredit list with the scene information so that the keyword list does notstore the keywords. Therefore, even when the description informationincludes many keywords, the data quantity of the keyword list can bekept small. Accordingly, the data quantity of the whole descriptioninformation including the keyword list can be small.

According to the second embodiment, it is not necessary to produce thekeyword list by extracting the keywords from the description informationso that the conversion processing of the description information can beperformed fast.

Third Embodiment

The second embodiment has been described in connection with the casewhere the keyword list stores all the scene information items eachincluding the keyword.

A third embodiment will now be described in connection with the casewhere the description information additionally includes information thatspecifies, for each keyword, the other scene(s) in which the samekeyword is present.

A storage device according to the third embodiment has substantially thesame structure as storage device 102 according to the second embodimentshown in FIG. 10, and therefore description thereof is not repeated.

FIG. 13 illustrates examples of description information 500, credit list406 and an entry list 506.

Credit list 406 is substantially the same as that in the secondembodiment, and therefore description thereof is not repeated.

Referring to FIG. 13, the keyword included in description information500 is converted into reference information 502 specifying the keywordin credit list 406 as well as link information 504 specifying the sceneswhere the same keyword is present.

Reference information 502 is ID information 408 for specifying keywordvalue 410 stored in credit list 406.

Link information 504 represents the scene information about the nextscene in which the same keyword will appear.

For example, link information 504 “next=2” is added to the keyword“Akira ABE” indicated by reference information 502 “ref=1” included inthe scene [1]. This link information 504 “next=2” represents that thesame keyword “Akira ABE” will appear in a second scene from the currentscene. Thus, the scene [3] that is the second scene from the scene [1]includes the same reference information 502 “ref=1” for specifying thekeyword “Akira ABE”. Since link information 504 corresponding toreference information 502 “ref=1” included in the scene [3] is “next=1”,the same keyword will appear in the next scene [4]. Link information 504of reference information 502 “ref=1” included in the scene [4] is“next=0”. Link information 504 “next=0” represents that the same keywordwill not appear in the subsequent description information, and entrylist 506 is referred to when link information 504 “next=0” is received.

Entry list 506 stores the scene information of the scenes eachcorrelated with the keyword which appears first in the descriptioninformation. In the foregoing example, when entry list 506 is referredto according to link information 504 “next=0”, the entry pointcorresponding to the ID number “1” correlated with the keyword “AkiraABE” is the scene [1].

As described above, all the scenes including the keywords “Akira ABE”can be obtained by substantially circulating through descriptioninformation 500 and entry list 506.

The link information may be required merely to indicate linkages aboutthe scenes in which the same keyword is present. Alternatively, it mayindicate next storage positions of the same keywords (specifically, ofthe reference information indicating the same keywords). Therefore, thelink information may be provided by the path information of the tree, ormay be implemented using the data positions (absolute/relativeaddresses) where the reference information is stored, or offsetdistances to the next reference information storage positions.

According to the third embodiment, the scene information containing therespective keywords is described in the description information so thatthe entry list has a constant size regardless of the data quantity ofthe description information. The scene information items described inthe description information are mutually linked. Therefore, when thescenes including the same keyword are to be continuously retrieved, orin a similar case, the storage capacity can be reduced as compared withthe case where all the scene information is to be obtained in advance.

Fourth Embodiment

In the first to third embodiments described above, the list correlatingthe keywords with the reference information is separated from thedescription information.

In a fourth embodiment described below, the description informationcontains the list correlating the keywords with the referenceinformation.

A storage device according to the fourth embodiment has substantiallythe same structure as storage device 100 according to the firstembodiment of the invention shown in FIG. 3, and therefore descriptionthereof is not repeated.

Description information converter 8 in the fourth embodiment performsconverting processing on each of the keywords registered in the keywordlist produced by list producing portion 6, and particularly at oneposition of the description information such as a position where each ofthe keywords is first stored, and thereby converts the keyword into thekeyword data itself and the reference information for specifying thekeyword data. Further, description information converter 8 converts thekeywords that are the same as the keyword in question but are present indifferent positions, and more specifically converts the same keywords inthe description information into the reference information forspecifying the keywords in question.

FIG. 14 illustrates a example of the description information accordingto the fourth embodiment.

Referring to FIG. 14, description information converter 8 adds IDinformation 902 for specifying the keywords “Akira ABE”, “Keiko KUBO”and “Wataru WADA” for scene [1] where these keywords are first stored.Each of the keywords stored after the scene [1] is converted intoreference information 904 correlated with ID information 902.

As described above, since the description information includes the listfor storing the respective keywords and the reference information in thecorrelated fashion, it is not necessary to store each keyword in aseparated fashion. Therefore, list producing portion 6 produces thekeyword list formed of the reference information and the sceneinformation, similarly to keyword list 412 illustrated in FIG. 12.

Further, storage 10 stores the description information provided fromdescription information converter 8 and containing the list thatcorrelates the keywords with the reference information, and also storesthe keyword list provided from list producing portion 6 and correlatingthe reference information with the scene information.

In view of data error resistance, the same keyword and the same IDinformation may be described at a plurality of positions in thedescription information so that these can be referred to at eachposition.

According to the fourth embodiment, since it is not necessary to storethe list of the keywords correlated with the reference information, thedetails of the movie can be described using only the data in thedescription information. Therefore, even when the descriptioninformation for many movies is present, it is required to process onlythe reference information so that the information can be handled moreeasily than the case where the reference information and the lists areto be processed simultaneously.

According to the fourth embodiment, the data can be held without causingany change in format of the original description information. Therefore,a routine for newly interpreting a data format is not required, and theoriginal description information and the converted descriptioninformation can be handled in substantially the same manner.

Fifth Embodiment

FIG. 15 schematically shows a structure of a storage device 104according to a fifth embodiment of the invention.

Referring to FIG. 15, storage device 104 is formed of a computer 40, aninput 32 and an output 34.

Computer 40 includes a CPU (Central Processing Unit) 20 executingprograms, a ROM (Read Only Memory) 22, a RAM (Random Access Memory) 24and an HDD (Hard Disk Drive) 26 for storing the programs and data, aninterface 28 for connection to external record devices such as a DVD(Digital Versatile Disk) and a memory card, a communications device 30for connection to various communications networks including theInternet, and a bus 36 for data transmission/reception between varioussections and portions.

Input 32 is formed of a keyboard, a mouse, buttons and the like.

Output 34 is formed of a monitor, a speaker, a display and/or the likethat display or output movies, sounds, characters and the like.

ROM 22, RAM 24 or HDD 26 stores a keyword determining program, aposition information extracting program, a list producing program and adescription information converting program that implement keyworddetermining portion 2 or 52, position information extractor 4 or 54,list producing portion 6 or 56 and description information converter 8or 58 in storage device 100 or 102 according to the first to fourthembodiments, respectively. CPU 20 loads and executes the storedprograms. Alternatively, the above various programs may be recorded onan external record medium of a computer-readable type, and the devicemay be configured to load the programs therefrom via interface 28 forexecuting the programs.

CPU 20 externally receives the description information, and stores it inRAM 24 or HDD 26.

CPU 20 executes the loaded keyword determining program. Thereby, CPU 20reads the keywords included in the description information stored in RAM24 or HDD 26, compares them with the keywords included in the keywordlist stored in RAM 24 or HDD 26 and determines whether the keywords inquestion are registered or not.

CPU 20 executes the loaded position information extracting program, andextracts the scene information corresponding to the keywords.

CPU 20 executes the loaded list producing program, and operatesaccording to the result of the determination by the keyword determiningprogram to register newly or additionally the keywords and the sceneinformation of the keywords in the list that is stored in RAM 24 or HDD26.

Further, CPU 20 executes the loaded description information convertingprogram. Thereby, CPU 20 converts the keywords in the descriptioninformation stored in RAM 24 or HDD 26 into the reference informationaccording to the list stored in RAM 24 and HDD 26, and records thedescription information thus converted in RAM 24 or HDD 26. Further, CPU20 records the keyword list and the entry list produced by the listproducing programs as well as the externally received credit list in RAM24 or HDD 26.

Instead of directly overwriting the original description informationwith the information thus changed, the description information may becopied to RAM 24 or HDD 26, and the copied description information maybe converted.

CPU 20 may record the converted description information on an externalcomputer-readable medium via interface 28. Further, CPU 20 may record iton another device via a communications network connected tocommunications device 30.

The computer-readable mediums storing the description information,keyword list, entry list, credit list and the like are not restricted toROM 22, RAM 24 and HDD 26, and may be mediums fixedly bearing thedescription information such as a flexible disk, cassette tape, MO(Magneto-Optical Disk), MD (Mini Disk), DVD- (Digital Versatile Disk-)ROM/RAM/R/RW, SD memory card, IC card (including memory card), opticalcard, mask ROM, EPROM, EEPROM, flash ROM and other semiconductormemories.

According to the fifth embodiment, since transmission/reception of datasuch as description information to/from another device can be readilyperformed via the record medium or communications network, even a moviereproducing device not having a function of efficiently storing thedescription information can achieve substantially the same effects asthose in the first to fourth embodiment.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

1. A storage device for storing description information includingkeywords describing multimedia contents, comprising: descriptioninformation conversion means for generating said description informationby replacing each remaining keyword except for at least one keyword,among keywords identical to each other included in original descriptioninformation, with reference information specifying said at least onekeyword, and storage means for storing said description informationoutput from said description information conversion means, wherein aplurality of scenes constitute said multimedia contents, said referenceinformation is described to specify the identical keyword added to acertain scene, and the certain scene precedes in time the scenecorresponding to said reference information.
 2. The storage deviceaccording to claim 1, wherein each said at least one keyword in saidoriginal description information has ID information representing itselfadded, and said reference information includes information indicatingsaid ID information added to a keyword not being subjected toreplacement with reference information.
 3. A computer-readable storagemedium storing description information including keywords describingmultimedia contents, wherein said description information is configuredby replacing each remaining keyword except for at least one keyword,among keywords identical to each other included in original descriptioninformation, with reference information specifying said at least onekeyword, and said storage medium being read by a computer, said computerresponsive to a selection of a keyword to retrieve a position where aselected keyword is located in said multimedia contents, referring tosaid description information stored in said storage medium, wherein aplurality of scenes constitute said multimedia contents, said referenceinformation is described to specify the identical keyword added to acertain scene, and the certain scene precedes in time the scenecorresponding to said reference information.
 4. The computer-readablestorage medium according to claim 3, wherein each said at least onekeyword in said original description information has ID informationrepresenting itself added, and said reference information includesinformation indicating said ID information added to a keyword not beingsubjected to replacement with reference information.